The invention relates to automated milking parlors, and more particularly to a method for correcting improperly identified cows which may have a lost or malfunctioning identification tag, or otherwise are misidentified.
Milking parlors with automatic cow identification systems are known in the prior art, for example as disclosed in U.S. Pat. Nos. 5,028,918, 5,183,008, incorporated herein by reference. The parlor typically has an identification sensor at the entrance and/or exit, which sensor includes a transmitter antenna and a receiver antenna for communicating with a transponder in an identification tag on a collar around the neck of the cow. The transponder in the identification tag includes an electronic oscillator circuit triggered by interrogating electromagnetic RF radiation from the transmitter antenna and sending back a coded identifying signal in response to the interrogating pulse, which signal is received by the receiver antenna. The coded identifying signal is an individual unique identification code identifying that particular cow.
The cows initially enter the parlor at a small holding pen, and then pass serially through an entrance having the noted identification antenna system, and then into plural parallel milking stalls, with the first cow entering stall number 1, the second cow entering stall number 2, and so on. The identification system correlates the cow passing through the antenna system with the stall receiving such cow. In this manner, it is known which cow is in which stall, and in turn milk production can be correlated and tracked for each cow.
A problem arises if a cow passing through the entrance antenna system has lost her tag or has a malfunctioning tag, in which case there is no coded response signal sent back to the receiver antenna and hence no cow identified. The respective stall thus has an unidentified cow therein, and the computerized tracking system will think that the next trailing cow is in such stall location. For example, if the fifth cow to pass serially through the entrance has a missing tag, such fifth cow will in turn pass into stall location number 5. However, the computerized identification system will not register a fifth response coded signal until the sixth cow, and hence will correlate the sixth cow to stall location number 5, i.e. the computer does not see or register or identify cow number 5, and instead identifies the sixth cow as cow number 5 and thinks that such sixth cow is in stall number 5. Likewise, all succeeding cows will be misidentified by one stall location, i.e. improperly correlated to the wrong stall.
In small dairies, the above problem is not a significant drawback because the milking personnel know the cows and can correct missed identifications. However, in large parlors, a misidentification can become a significant problem, particularly when the milkers do not know the cows well enough to correct errors. In addition to absent or malfunctioning tags, misidentifications may be caused when a cow enters with her tag in an unreadable position, electronic noise interference, and so on. Even if the error or misidentification rate is low, e.g. less than one percent, a significant problem can arise depending upon where such error occurs in the serial flow of cows through the entrance. For example, if one of the last cows serially entering the parlor has a missing tag, then only the few cows thereafter will also be misidentified. However, if one of the first cows serially entering the parlor has a missing tag, then each of the cows thereafter will be correlated to the wrong stall number. Furthermore, if a second cow has a missing tag, then further cows after such second cow will be miscorrelated by two stall locations.
The present invention addresses and solves the noted misidentification problem in a simple and effective manner.